100% Noninductive Operation at High Beta Using Off-Axis ECCD by M. - PowerPoint PPT Presentation

100% Noninductive Operation at High Beta Using Off-Axis ECCD by M. Murakami in collaboration with C.M. Greenfield, 2 M.R. Wade, 1 T.C. Luce, 2 , J.R. Ferron, 2 H.E. St. John, 2 M.A. Makowski, 3 M.E. Austin, 4 S.L. Allen, 3 D.P. Brennan, 5 K.H. Burrell, 2 T.A. Casper, 1 J.C. DeBoo, 2 E.J. Doyle, 6 A.M. Garofalo, 7 P.Gohil, 2 I.A. Gorelov, 2 R.J. Groebner, 2 J. Hobirk, 8 A.W. Hyatt, 2 R.J. Jayakumar, 3 K. Kajiwara, 5 C.E. Kessel, 9 J.E. Kinsey, 10 R.J. La Haye, 2 J.Y. Kim, 2 L.L. Lao, 2 J. Lohr, 2 J.E. Menard, 9 C.C. Petty, 2 T.W. Petrie, 2 R.I. Pinsker, 2 P.A. Politzer, 2 R. Prater, 2 T.L. Rhodes, 6 A.C.C. Sips, 8 G.M. Staebler, 2 T.S. Taylor, 2 G. Wang, 6 W.P. West, 2 L. Zeng, 6 and the DIII–D Team 1 Oak Ridge National Laboratoty, Oak Ridge, Tennessee, USA 2 General Atomics, P.O. Box 85608, San Diego, California, USA 3 Lawrence Livermore National Laboratory, Livermore, California, USA 4 University of Texas at Austin, Austin, Austin, Texas, USA 5 Oak Ridge Institute for Science Education, Oak Ridge, Tennessee, USA 6 University of California at Los Angeles, Los Angeles, California, USA 7 Columbia University, New York, New York, USA 8 Max-Planck-Institut for Plasmaphysiks, Garching, Germany 9 Princeton Plasma Physics Laboratory, Princeton, New Jersey, USA 10 Lehigh University, Bethleham, Pennsylvania, USA Presented at 20th IAEA Fusion Energy Conference Vilamoura, Portugal November 2, 2004 DIII–D NATIONAL FUSION FACILITY S A N D I E G O

DIII-D AT PROGRAM GOAL: SCIENTIFIC BASIS FOR STEADY STATE, HIGH PERFORMANCE OPERATION IN FUTURE TOKAMAKS 0.5 � Steady-state operation Normalized fusion performance, G DIII-D — 100% noninductive fraction: f NI = I NI /I p AT Baseline Hybrid — High Bootstrap current fraction: f BS = I BS /I P � � p target 0.4 regime regime � Maintaining sufficient fusion gain with reduced engineering parameters 0.3 — Hgh � T — High � E 0.2 � High Normalized fusion performance: G = � N H/q 2 ITER glf23 simulation � DIII-D AT experiments have demonstrated ITER Q~5 (f NI =1) performance required for ITER steady state steady state 0.1 scenarios scenario High β p, high q regime 0.0 0.0 0.2 0.4 0.6 0.8 Bootstrap current fraction, f BS T. Luce: OV1-3 G. Sips: IT/P3-36 10/31/04: IAEA2004:v3.3 -- MM

100% NONINDUCTIVELY DRIVEN PLASMAS OBTAINED WITH GOOD CURRENT DRIVE ALIGNMENT EQUILIBRIUM MEASUREMENTS 150 Toroidal Current Density (A/cm ) 2 120096.4160 J tot 100 50 J OH 0 –50 0.0 0.2 0.4 0.6 0.8 1.0 RADIUS, ρ � f NI = 1 – f OH ; J OH = � neo E | | � � neo �� pol / � t � f OH = 0.5%, f NI = 99.5% � � T = 3.5%, � N = 3.6, q 95 = 5.4 10/31/04: IAEA2004:v3.3 -- MM

CRITICAL ISSUES COVERED IN THIS TALK Self- c onsistent solutions for full noninductive, high performance operation � requires: 1. f NI = 100% 2. Good current drive alignment 3. Pressure profile evolution stable for ideal MHD and NTMs 4. Current profile stops evolving (E | | � 0 everywhere) Predictive modeling: � — Validated by the experiment — Projects longer sustainment of 100% noninductive in DIII-D — Applied to the ITER steady-state scenario development 10/31/04: IAEA2004:v3.3 -- MM

PREDICTIVE SIMULATIONS INDICATE PREVIOUS ECCD DISCHARGE COULD BE EXTENDED TO 100% NONINDUCTIVE WITH INCREASED NBI POWER Modeling Modeling 1.2 1.5 Non-Inductive Current Fractions J ( ρ ) t = 7.0 s [ ] MA/m 2 Jtotal 1.0 fNI(t) 1.0 0.8 J shot 111221 NBCD 0.6 J BS 0.5 20 P (t) J ECCD inj 0.4 4 MW 0 10 [MW] 0.2 J OH P ECCDj -0.5 0.0 0 0.0 0.2 0.4 0.6 0.8 1.0 2 3 4 5 6 7 Time (s) Normalized Radius, ρ � Two tr ansport models produce consistent results: — Scaled experimental transport coefficients — Recalibrated GLF23 10/31/04: IAEA2004:v3.3 -- MM

WITH HI GHER NBI POWER, 100% NONINDUCTIVE CURRENT ACHIEVED, BUT NOT FULLY RELAXED 16 1.0 114741 12 P inj (MW) 8 0.5 J OH ( ρ ) @ t = 3.12 s MA/m 2 P EC 4 0 0.0 1.2 f NI (TRANSP) TRANSP 0.8 f NI (NVLOOP) -0.5 NVLOOP 0.4 f BS 0.0 -1.0 2.4 2.6 2.8 3.0 3.2 3.4 3.6 0.0 0.2 0.4 0.6 0.8 1.0 TIME (s) Radius, ρ � Achi eved net f NI � 100 % with � N � 3.5, � � 3.6% � However, local Ohmic current is NOT zero 10/31/04: IAEA2004:v3.3 -- MM

WITH HIGHER NBI POWER, 100% NONINDUCTIVE CURRENT ACHIEVED, BUT NOT FULLY RELAXED 16 1.0 12 P inj (MW) J OH ( ρ ) at t = 3.12 s 8 0.5 MA/m 2 P EC TRANSP 4 0 0.0 1.2 f NI (TRANSP) f NI (NVLOOP) 0.8 –0.5 NVLOOP 0.4 f BS –1.0 0.0 0.0 0.2 0.4 2.5 0.6 0.8 1.0 q 0 Radius, ρ 2.0 1.5 q min � Achieved net f NI � 100 % with � N � 3.5, � � 3.6% 1.0 20 � However, local Ohmic current i s NOT zero |B| n=1 (G) � Neutral beam overdrive near the axi s 10 n=2 decreases q 0 , resulting in NTM s n=3 0 � Confinement somewhat degraded (large P NB 2.4 2.6 2.8 3.0 3.2 3.4 3.6 demand) in these discharges Time (s) — Rotation velocity often slower — Flatter q profiles ... often more monotonic 10/31/04: IAEA2004:v3.3 -- MM

IMPROVED CONFINEMENT RESULTS IN REDUCED NEUTRAL BEAM CURRENT DRIVE NEAR THE AXIS 90 80 NBCD (0) (A/cm ) 2 70 60 50 40 J 30 20 1.4 1.6 1.8 2.0 2.2 2.4 2.6 H 89 � Confinement improvement in recent experiments is attributed to: — Optimized non-axisymmetric field feedback — Slightly negative central shear 10/31/04: IAEA2004:v3.3 -- MM

WITH IMPROVED CONFINEMENT, f NI =100% ACHIEVED WITH GOOD CD ALIGNMENT 200 150 Local toroidal current density (A/cm ) 2 MSE Array 120096F05 Flux Surface Averaged Toroidal 〈 J( ρ ) 〉 Tangential Radial Current Density (A/cm ) 2 Edge 150 100 J tot Analysis (EFIT) J φ(ρ) 100 50 0 50 J OH (NVLOOP) 0 –50 2.0 2.2 2.4 1.6 1.8 0.0 0.2 0.4 0.6 0.8 1.0 Midplane major radius, R (m) RADIUS, ρ � f OH = 0.5%, f NI = 99.5% 10/31/04: IAEA2004:v3.3 -- MM

WITH IM PROVED CONFINEMENT, f NI =100% ACHIEVED WITH GOOD CD ALIGNMENT 200 150 Local toroidal current density (A/cm ) 2 MSE Array 120096F05 Flux Surface Averaged Toroidal 〈 J( ρ ) 〉 Tangential Radial Current Density (A/cm ) 2 Edge 150 100 J tot Analysis (EFIT) J φ (ρ) J boot J NB 100 50 J EC 0 50 JOH J OH (NVLOOP) 〈 J J 〉 (calc.) (calc.) EC EC (TRANSP) 0 –50 2.0 2.2 2.4 1.6 1.8 0.0 0.2 0.4 0.6 0.8 1.0 Midplane major radius, R (m) RADIUS, ρ � f OH = 0.5%, f NI = 99.5% � Anal ysis shows: f BS =59% f NB =31% f EC = 8% f NI = 98% � Cha llenge: — Measurement: Local representation in EFIT, . . . — Analysis/modeling: Bootstrap model near axis and edge, . . . � These analyses indicate achi evement of f NI � 100% 10/31/04: IAEA2004:v3.3 -- MM

PRESSURE PROFILE EVOLUTION RESULTED IN n=1 FAST GROWING MODE WHICH TRIGGERED n=1 NTM 120096 4 (h) 6 β N 3 100 p(0)/ 〈 p 〉 (gauss) 2 n=1 ~ n e (0)/ 〈 n e 〉 |B| Unstable 1 10 0 Fit to modeling data |B| n=1 (G) 4 for n=1 beta limit 5 4095 4091 TIME (ms) t = 4.09 s 0 5.0 2 2.5 |B|n=2 (G) 0 t = 0.4 s 5.0 t = 4.8 s 0 2.5 1 2 3 4 5 |B|n=3 (G) Pressure peaking facor, p(0)/ 〈 p 〉 0 3.2 3.4 3.6 3.8 4.0 4.2 4.4 Time (s) � n=1 ideal instability caused by pressure peaking primarily due to density peaking � Sustai ned n=1 NTM terminates high performance phase J. Ferron: EX/P-2-20 10/31/04: IAEA2004:v3.3 -- MM

NEARLY FULL NONINDUCTIVE, STATIONARY DISCHARGE OBTAINED, LIMITED ONLY BY GYROTRON PULSE LENGTH 10 118419 MSE Channels 1 - 11 5 MSE Pitch 0 Angle (deg.) –5 –10 4 gyrotrons → 3 ECCD ECCD –15 2.5 3.0 3.5 5.0 4.0 4.5 TIME (s) � M SE signals stationary � J � ( � ) stopped evolving � f NI ~ 90% for 1 � R (=1. 8s ) � � T = 3.7%, � N = 3.5, q 95 = 5.1 � G= � N H/q 2 = 0.3 with f BS =63% 10/31/04: IAEA2004:v3.3 -- MM

GLF23/ ONETWO CAN REPRODUCE EXPERIMENTAL PROFILES REASONABLY WELL, AND ALSO CAN PREDICT STEADY STATE PERFORMANCE IN TOKAMAKS 8 15 2.0 160 keV 10 5 (rad/s) A/cm 2 Data (111221.03840) J tot ( ρ ) GLF23 ( +560 ms ) 6 1.5 120 10 Ti ( ρ ) 4 1.0 80 Ω tor ( ρ ) q ( ρ ) 5 2 0.5 40 Te ( ρ ) (a) (b) (c) 0 0 0.0 0 0.0 0.2 0.4 0.6 0.8 1.0 0.0 0.2 0.4 0.6 0.8 1.0 0.0 0.2 0.4 0.6 0.8 1.0 Radius, ρ Radius, ρ Radius, ρ � Good coupling between experiment and modeling 10/31/04: IAEA2004:v3.3 -- MM

GLF23/ONETWO CAN REPRODUCE EXPERIMENTAL PROFILES REASONABLY WELL, AND ALSO CAN PREDICT STEADY STATE PERFORMANCE IN TOKAMAKS 8 15 2.0 160 A/cm 2 keV 10 5 (rad/s) Data (111221.03840) J tot ( ρ ) GLF23 ( +560 ms ) 6 1.5 120 GLF23 ( steady state ) 10 Ti ( ρ ) 4 1.0 80 Ω tor ( ρ ) q ( ρ ) 5 2 0.5 40 Te ( ρ ) (a) (b) (c) 0 0 0.0 0 0.0 0.2 0.4 0.6 0.8 1.0 0.0 0.2 0.4 0.6 0.8 1.0 0.0 0.2 0.4 0.6 0.8 1.0 Radius, ρ Radius, ρ Radius, ρ � Good coupling between experiment and modeling � Numerical advance (global convergence technique) incorporated into ONETWO allows prediction of steady state in one step (without time stepping calculation) 10/31/04: IAEA2004:v3.3 -- MM